PROJECT SUMMARY This application proposes a customized research training plan designed to promote the development of the applicant into an independent investigator. The plan includes advanced training in both bioinformatics and laboratory experimentation, along with tailored professional and career development opportunities. The training plan is supported by the outstanding availability of local and institutional resources at UIC. The proposed research will examine the mechanisms that control scar formation, a common result of the healing response. Scars are a fibrous mass of disorganized collagen, extracellular matrix, and fibroblasts. Scar formation can lead to significant long term impairments of the organ system affected. Excessive scar formation is also a barrier to regenerative strategies, including those that target the complex tissues of the craniofacial region. One tissue that exhibits rapid and nearly scarless healing is the oral mucosa. Wound healing of oral mucosa is differentiated from cutaneous healing by a faster re-epithelialization, a shortened inflammatory phase, a brief angiogenic response, and minimal scar formation. The goal of this project is to gain a comprehensive understanding of the transcriptional regulation of wound healing over time in the oral mucosa and skin. The research plan utilizes a systems biology approach to learn how the oral cavity implements a scarless transcriptional response to injury, and how the skin healing response leads to scarring. We hypothesize that the transcriptional regulatory networks of oral and cutaneous wounds are intrinsically different, and that gene regulation by key transcription factors is responsible for the differential healing phenotypes between these two tissues. Utilizing a unique human microarray dataset of >95 samples from experimental skin and gingival wounds, our studies will focus on transcription factors (TFs), proteins that can activate or repress the transcription of a large number of genes in a coordinated fashion. Aim 1 will utilize a network- based approach to identify TFs that orchestrate the dynamic gene expression changes in wound healing of human gingiva and skin. Specifically, Aim 1 will a) identify TFs that uniquely target genes in oral or skin healing, b) discover shared TFs that regulate wound healing in both tissues, and c) predict candidate scar- promoting TFs. Downstream biological pathways targeted by these TFs will be discerned. Aim 2 will utilize in vivo and in vitro wound models to determine the role of candidate scar-promoting TFs. We will use an in vivo siRNA-based approach to knock down candidate scar-promoting TFs in murine skin wounds. TFs whose in vivo repression leads to decreased scar formation and/or accelerated wound closure will be further studied in more extensive in vivo mechanistic studies. In vitro studies will provide mechanistic information about these critical TFs. Together, the Aims will provide new information about the role of TFs in the transcriptional regulation of scar formation. The findings will be applicable to a wide variety of conditions, including burns, chronic wounds, hypertrophic scars, keloid formation, skin regeneration, and other fibrotic pathologies.